/*
 * EnumTransform.java May 2007
 *
 * Copyright (C) 2007, Niall Gallagher <niallg@users.sf.net>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */

package wx.xml.simpleframework.xml.transform;

/**
 * The <code>EnumTransform</code> represents a transform that is
 * used to transform enumerations to strings and back again. This
 * is used when enumerations are used in comma separated arrays.
 * This may be created multiple times for different types.
 *
 * @author Niall Gallagher
 */
class EnumTransform implements Transform<Enum> {

    /**
     * This is the specific enumeration that this transforms.
     */
    private final Class type;

    /**
     * Constructor for the <code>EnumTransform</code> object. This
     * is used to create enumerations from strings and convert them
     * back again. This allows enumerations to be used in arrays.
     *
     * @param type this is the enumeration type to be transformed
     */
    public EnumTransform(Class type) {
        this.type = type;
    }

    /**
     * This method is used to convert the string value given to an
     * appropriate representation. This is used when an object is
     * being deserialized from the XML document and the value for
     * the string representation is required.
     *
     * @param value this is the string representation of the value
     * @return this returns an appropriate instanced to be used
     */
    public Enum read(String value) throws Exception {
        return Enum.valueOf(type, value);
    }

    /**
     * This method is used to convert the provided value into an XML
     * usable format. This is used in the serialization process when
     * there is a need to convert a field value in to a string so
     * that that value can be written as a valid XML entity.
     *
     * @param value this is the value to be converted to a string
     * @return this is the string representation of the given value
     */
    public String write(Enum value) throws Exception {
        return value.name();
    }
}